Of Keys, Slayers, and Cruel Intentions
by Gabby2
Summary: NEWLY REVISED! NEW CHAPTER! Instead of the monks making Dawn the key, Kathryn Merteuil is created to be Buffy’s twin sister. And what happens when the handsome Sebastian Valmont is thrown into the mix? Spoilers for seasons 1 through 5 and Cruel Intentions
1. Chapter 1

**Title: **Of Keys, Slayers, and Cruel Intentions

**Author: **Gabby

**Summary: **Instead of the monks making Dawn the key, Kathryn Merteuil is created to be Buffy's twin sister. And what happens when the handsome Sebastian Valmont is thrown into the mix? Spoilers for seasons 1-5 and Cruel Intentions.

**Rating: **R

**Disclaimer: **Not mine. All Buffy is owned by Joss Whedon. And Cruel Intentions is owned by…some other brilliant person who's name I don't know off the top of my head.

**Author's Note: **My first Cruel Intentions story, but definitely not first Buffy, first crossover, or first fanfic! I'll update as often as possible, if I don't it's because school or something interferes, I have the whole plot and story line down… it's just typing it and getting it posted. Feel free to leave comments and constructive criticism, but please no flames. Enjoy!

**Second IMPORTANT Author's Note:** New and revised!! Sorry it took so long for me to update. Please review! Enjoy!

**-----------**

Buffy hung up the phone and turned around to look at the gang, "Damn". She sighed heavily and plopped down next to Riley. She aggressively pulled her long, blonde hair up into a messy ponytail. She put her head on his shoulder as they group gave her a quizzical look.

"My lovely twin, Kathryn," Buffy sighed again, "Yes Xander," she added after seeing the look of joy and ecstacy on his face, "the hot one."

At this Anya smacked Xander on the arm and proceeded to talk, "Well if they're twins they _**must**_ look the same." Buffy smiled, thinking Anya was being awfully nice, until she continued that is, "And _**if**_ they look the same I _**sure**_ don't see why you would… I mean _**look**_ at her."

Xander's eyes widened in horror and slapped a hand over Anya's mouth. He turned to Buffy, "You're beautiful Buff."

"Yeah, you are," Riled stated, kissing Buffy's head.

Willow shrugged at Buffy as Tara walked in. Tara sat down next to Willow and asked, "What's up?"

"Attack of Miss-I-Don't-Know-When-to-Shut-the-Hell-Up," Willow answered, inclining her head toward Anya.

"Hey-" Anya started.

"So, Buffy," Riley cut her off, "What'd your sister want?"

"Sister?" Tara questioned, wrapping her hair around her finger. "You have a sister?"

"Twin actually," Buffy supplied, "Kathryn Merteuil. She stayed with dad after the divorce."

"Merteuil?"

"Yeah, that's my dad's last name. Summers is my mom's maiden name. We both took it after the divorce. She just called a few minutes ago."

"Okay, so what did she want?"

"Well it turns out dear old dad got remarried. Didn't bother to tell us of course. So my new step mom is some cheesy ex-debutant, probably already sleeping around with the pool boy, with _**daddy**_ watching on, oblivious. Oh, the icing on the cake? I gained a new stepbrother, Sebastian Valmont."

"Sebastian? Like the singing crab from The Little Mermaid?" Anya asked, perking up.

"Yes Anya, I'm sure he's that same dazzling shade of red too," Buffy snapped back.

Xander snorted a laugh and pretended to cough to cover it up.

"Oh, there's a cherry on top… they're in town. I guess dad called my mom and asked if Kathryn and Sebastian could stay with us while he and his new wifie go on an 'extended honeymoon'. I just love how much my mom shares with me."

"When are they showing up?" Willow asked.

"Tomorrow," Buffy groaned, "at noon."

**----------**

"_**This **_is _**it**_?" Kathryn snapped, setting her bags down and looking around the Sunnydale airport. She perched her size two frame, swathed in a Gucci wrap dress, on one of the old plastic chairs. "Fuck."

"At least we're not _**there**_ anymore," Sebastian stated, sitting down on another one of the plastic chairs. He fiddled with one of the buttons on his Armani blazer.

"You only wanted out of there because Ronald was pissed off about Cecile."

"Yes… and how could he have found out I wonder… " Sebastian said sarcastically, eyes boring into Kathryn.

Kathryn shrugged, smiling sweetly.

"Is that them?" Sebastian questioned, looking toward the entrance of the lobby.

Kathryn turned and saw Buffy and Joyce walking toward them. "Fuck me," she sighed deeply and then instantly perked up, "Mom! Buffy!"

Sebastian laughed to himself and thought, _**She**__** is so fake.**_ He stood up as Joyce and Buffy hugged Kathryn.

"Sebastian Valmont," he said, extending his hand once they were done.

"Joyce Summers," Joyce spoke warmly, her brown eyes sparkling happily.

"Buffy," she said, not sounding the least bit interested, "Guess you're my new… er… brother."

"Stepbrother," Sebastian corrected her, "Not blood related."

Buffy laughed cautiously. Sebastian cocked and eyebrow at her. She was quite different than Kathryn. Her hair was long and blonde, instead of dark brown and the shorter cut Kathryn favored. She didn't appear to insist on wearing expensive designer clothes to make sure she stood out in the crowd. Her eyes were warm where Kathryn's were mostly cold. She also laughed, which wasn't one of Kathryn's favorite things to do. Her handshake was also surprisingly strong.

"Best get to the Land Rover before something happens to it," Joyce smiled.

Sebastian inwardly groaned and wished he had his beloved Jaguar.

**----------**

"Sure I'll keep an eye on him cuz," Gunn said into the phone, "No problem man."

Angel walked in as Gunn hung up the phone, "Who was that?"

"My cousin, Ronald. Needs me to keep an eye on someone. Mind if I'm out of town for a bit?"

"Sure, we should be able to hold the fort down."

Gunn nodded, picked up his Adidas sports bag, and headed out to his truck.

"Sunnydale here I come," he said, starting the engine, not knowing who Buffy was and how she could be tangled up in this.

**----------**

"Uh, this is Willow, Xander, Tara, and Anya," Buffy said gesturing to each respectively.

They all muttered a greeting to a bored looking Kathryn and slightly amused Sebastian. Kathryn took in the group. The redhead – Willow, was it? – was apparently into the whole environment thing or something, considering she was wearing what looked like some organically made shirt. Kathryn shuddered, _**Crunchy**_ Xander kind of made her think of a male Cecile, but maybe a little more sexually inclined. One would hope. Tara was dressed similarly to Willow and had an amulet around her neck. Anya beamed up at her and appeared to be eyeing her purse as well. Kathryn instinctively pulled it closer. Anya then turned to look at Sebastian.

"He's not red," she stated matter-of-factly.

The rest of the Scoobies looked horrified while the newcomers looked confused.

Buffy quickly changed the subject, "Wanna see where your rooms are?"

Kathryn and Sebastian followed Buffy up the stairs. Buffy walked to the spare bedroom, which was decorated with fleur-de-lis print, and said, "Sebastian you can stay in here," Kathryn elbowed him and snickered, "and Kathryn…" Buffy trailed off and walked through the bathroom that joined her room and the guest bedroom, "you can stay with me." Kathryn's eyes took in the old New Kids on the Block posters and butterflies that were on the walls. She saw collages of pictures of the gang over the years. She looked at Buffy's bed, which differed a lot from hers, crocheted pillows and all. She then looked to the cot in the corner of the small room and her eyes narrowed, "Is that mine?" Buffy nodded at her and forced a smile. Kathryn's stomach turned, _**It's probably polyester. Damn.**_

Sebastian smirked at the anger that was plastered across Kathryn's face. He turned and looked at Buffy, who was standing there as if unsure what to do. He never would have guessed they were sisters… except for the whole twin thing. Kathryn was such a bitch and Buffy was… well, not.

"I'm starving," he said, breaking the silence.

"Oh!" Buffy said, coming to life, "Follow me."

As they walked down the stairs they could hear the gang chatting in the living room.

"An… I can't believe you said that," Xander sighed.

"What?" Anya questioned.

"Miss Motor-Mouth strikes again," Willow said flippantly.

Buffy shook her head and went to go into the kitchen, but before she could the doorbell rang. She quickly walked over to the door and opened it. Riley stood in the doorway. He kissed Buffy and followed her into the kitchen where her… siblings… had found some food. Kathryn looked at the warmed up macaroni on her plate with distain. Sebastian was perched on a stool eating chips out of a bag.

Kathryn perked up when she saw Riley and touched her hair, "Who might this be?"

"My boyfriend, Riley Finn," Buffy told her.

Kathryn's face visibly slackened. Sebastian looked at her as if to say "Always the little twits?".

**----------**

Buffy and the gang were sitting at a table in the Bronze. Kathryn and Sebastian had gone to the bar.

"Buffy… he's pretty damn hot," Willow noted and quickly shot an apologetic look at Tara.

"This coming from _**you**_," Anya added.

"Anya, would you just _**shut up**_?" Willow fumed.

Xander, noticing the tension, got up and drug Anya onto the dance floor.

"What's up with you and Anya?" Buffy asked Willow, taking a sip of her pink drink.

"She's just been extra… I dunno… Anya-ish lately." Willow shrugged, "So about Sebastian… "

"You mean my _**stepbrother**_."

"You're not blood related stepbrother. Yes, about Sebastian… "

"What about me?" he asked, smiling as he and Kathryn sat back down. Kathryn straightened her Louis Vuitton black pleated skirt and smirked at Buffy, challenging her.

"Um, uh… " Buffy tried and glanced at Willow, who shrugged, "Wanna… er… dance?"

Sebastian seemed to be taken by surprise, but nodded, "Sure."

They got up and headed out onto the dance floor. Buffy thought it would be odd dancing with Sebastian, but it wasn't even as if he was her stepbrother.

_**Not blood related**_, she told herself, just as the others had, _**Besides, I'm with Riley, so it's not like I'm **_**with**_** him. But why am I slightly happy Riley's not here?**_

"You're so tense sis," Sebastian echoed what he had said to Kathryn not so long ago.

"What?" Buffy asked stupidly, thrown off by Sebastian calling her "sis".

"Are you okay? You seem tense."

"Oh, just a lot on my mind," she said, just realizing they didn't know she was the Slayer and that she was going to have to sneak around again.

**----------**

_**This is pathetic**_, Buffy thought to herself while sneaking around and trying not to wake Kathryn, who was zonked out on the cot with a mask over her eyes, _**I haven't had to sneak out since junior year.**_

She quietly let herself out of the room and snuck down the stairs. She slipped on her zip up hoodie and headed out the door. She jogged down the street and headed toward the docks. She looked around cautiously for any sign of movement. She saw something move to her right and she ran after it.

Buffy chased the creature until they reached a chain link fence. She cornered the fledgling, probably just in high school judging by its clothes and look of superiority, and quickly staked it. When she brushed the dust off of her she looked down and saw a glowing, yellow orb. She knelt down to pick it up when she heard a voice behind her.

"There's no rave here missy. You should go before the cops come," an overweight security guard in a old, faded, blue uniform told her, shining a flashlight into her eyes.

Buffy squinted at him and said, "Sorry… my bad. So many parties, so little time."

"What's that?" he asked, gesturing toward the orb.

"Oh you know… typical rave light thing-y."

He shook his head and walked away. Buffy looked at the orb quizzically and wondered to herself, _**What**__** exactly are you?**_


	2. Chapter 2

**Title: **Of Keys, Slayers, and Cruel Intentions

**Author: **Gabby

**Summary: **Instead of the monks making Dawn the key, Kathryn Merteuil is created to be Buffy's twin sister. And what happens when the handsome Sebastian Valmont is thrown into the mix? Spoilers for seasons 1-5 and Cruel Intentions.

**Rating: **R

**Disclaimer: **Not mine. All Buffy is owned by Joss Whedon. And Cruel Intentions is owned by…some other brilliant person who's name I don't know off the top of my head.

**Author's Note: **My first Cruel Intentions story, but definitely not first Buffy, first crossover, or first fanfic! I'll update as often as possible, if I don't it's because school or something interferes, I have the whole plot and story line down… it's just typing it and getting it posted. Feel free to leave comments and constructive criticism, but please no flames. Enjoy!

--------

"Are you as bored as I am?" Kathryn sighed, setting down her shopping bags and plopping down on a bench at the Sunnydale Mall. She grimaced when she realized she had gum on the bottom of her black Prada boot.

Sebastian smiled at her and nodded his head, "Of course."

"I think we should… oh, spice things up a bit? Dare to make a little wager?"

"Ah, my brilliant sister. What have you got in mind?"

Kathryn smiled, grabbed Sebastian's arm and pulled him down onto the bench. She let him sit there for a minute or so, mulling over what she could possibly ask him to do. Finally he sighed impatiently and asked, "What Kathryn?"

"I've seen the way you look at your 'sister'," Kathryn said, giving her glossy brown hair a toss.

"Excuse me?" Sebastian looked a little bewildered.

"Don't feel bad, you're not blood related… besides I think it's… cute," Kathryn practically spat the last word. "Here's the bet. You bed our little Buffy. If you fail I get your precious car and your gay little journal."

Sebastian started to protest but Kathryn cut him off, "Tsk tsk tsk, no interrupting. If you win… you get something you've always wanted but could never have."

Sebastian scoffed, "What's that?"

"Me," Kathryn smiled.

He stuck out his nicely manicured hand, "Deal."

--------

"I found it down by the docks," Buffy informed the gang, including Giles, which was gathered in her living room.

"Evil jellyfish monster?" Xander joked.

"Could we sell it?" Anya asked.

Willow glared at her and turned to Buffy, "I can look through books at home and at the shop, see if I can find anything."

"Thanks Will, that'd be great."

Before they could continue the phone rang. Buffy quickly picked it up and hit the glowing TALK button, "Hello?... Oh hi mom."

Buffy left the room to talk to her mom and the rest of the gang tried to figure out what the glowing orb could possibly be.

"I still think we should sell it," Anya voiced.

"No one cares what you think," Willow snapped.

"Hey!" Anya and Xander shouted at the same time.

"For goodness sake will you all be quiet!" Giles cut in.

They all looked at him sheepishly. Giles, red in the face, continued, "Tara and Riley are the only civilized people… aside from myself… in this room. Can we _**please**_ try to get on with this and figure out what this… orb… is?"

Everyone nodded and were about to start discussing again when Buffy came back into the room. She put the phone down and sat next to Riley.

"What's up Buff?" he asked, taking her hand.

"My mom. She said she wants Kathryn and I to spend 'quality time'. So tonight… that's what I'll be doing. See if you guys can find out anything else about the wanna be light saber and let me know as soon as you can."

--------

Gunn prowled one of Sunnydale's many graveyards, trying to get rid of some pent up energy. He had a stake in his right hand and a knife hidden up his other sleeve. He was itching to find the guy his cousin had sent him after, but right now wasn't the time.

He saw a shadow move to his left and he froze. He watched silently for a few more seconds before a vampire suddenly flew at him out of the bushes. Gunn punched the vamp in the jaw and kicked him in the gut. The vamp lashed out to punch him, but Gunn jumped back. He ducked another punch and tripped the vampire. The vamp fell to the ground and Gunn quickly dusted him.

Suddenly three more vamps appeared from behind the headstones.

"This is one hell of a trip," Gunn muttered.

--------

"So, Riley's not your first boyfriend then?" Kathryn asked, sounding rather surprised.

"Uh… no," Buffy answered, confused.

"How many would you say you've had?"

_**What kind of conversation is this?**_ Buffy asked herself, but then answered. "Well, Owen didn't really count." _**Considering I almost got him killed. **_"Then… there was Angel," Buffy stopped for a moment, but quickly started up again, "And then Scott and… well Parker shouldn't count either. Then Riley. So 3, give or a take."

"This Angel person," Kathryn prodded, "he seemed to have some sort of… impact… on you."

"Well, he was my first love," Buffy was surprised she was sharing this with her-never-there sister, but she continued, "We had some rough patches. Now he's off in L.A. How about you, boyfriend-wise?"

"You win some, you lose some," Kathryn answered nonchalantly.

"What about Sebastian?" Buffy almost kicked herself for asking.

"With boys, I wouldn't know." Buffy cringed because she hadn't made herself clear, and felt like a fool. "But with girls… " Kathryn trailed off.

"Yes?"

"He has an extensive list. I'm sure he hasn't talked to most of them in years. Probably not after the first date. He's a heartbreaker." _**Well that's a light way of putting it.**_

_**Hopefully he wasn't anything like Parker. **_"Did he just not call them after dinner and a movie… or… ?"

Kathryn laughed out loud at her sister's naïveté, "Some might call it that… or dinner and a show. Sometimes just a show."

Buffy's face paled, "Well he doesn't seem like the type to do that."

"You have a lot to learn dear sister, a lot to learn."

Buffy looked at her and then out the window into the night, _**So**__** do you.**_

--------

**Author's Note: **Sorry that the chapter's not as long as the last, but hope you enjoyed it! Thanks for the comments guys! Please keep reading and reviewing!

**You Know Who: **Always a pleasure to read your comments my dear. :-D

**Wickedmoemoe**She might… she might not… you will see. And I'm not an uber-fan of Riley either… so I think we're on the same brainwaves here.

**RavynJensen**I'm glad you like it so far! I'm still working on what I'm adding in and what I'm not. Any suggestions would be great as well!

**Krycek's**** Immortal Slayer: **Thanks so much for reading! And I'm excited about Kathryn's reaction as well!

**LadyJ**** of ****moonshallow**Parings so far are: Anya/Xander, Willow/Tara, Buffy/Riley (at the moment… 'cos it has to be… but like I said before… he's not my favorite), and the other two… we'll find out.

**Allen Pitt: **I'm glad you like it! And it is rather strange concept, heehee. I'm excited about writing it though. And there will be much with the wackiness.

**W1cked Angel: **I was just establishing character… and at this point in time Anya isn't their favorite person… or a lot of the time (for Willow at least). It'll all work out.

Again, thanks everyone!


	3. Chapter 3

**Title: **Of Keys, Slayers, and Cruel Intentions

**Author: **Gabby

**Summary: **Instead of the monks making Dawn the key, Kathryn Merteuil is created to be Buffy's twin sister. And what happens when the handsome Sebastian Valmont is thrown into the mix? Spoilers for seasons 1-5 and Cruel Intentions.

**Rating: **R

**Disclaimer: **Not mine. All Buffy is owned by Joss Whedon. And Cruel Intentions is owned by…some other brilliant person who's name I don't know off the top of my head.

**Author's Note: **My first Cruel Intentions story, but definitely not first Buffy, first crossover, or first fanfic! I'll update as often as possible, if I don't it's because school or something interferes, I have the whole plot and story line down… it's just typing it and getting it posted. Feel free to leave comments and constructive criticism, but please no flames. Enjoy!

--------

"So how was your 'chat' with our sister?" Sebastian asked, flopping down on the couch.

Joyce had gone to work at the gallery and Buffy had run off somewhere, so the two had the house to themselves. Kathryn primly sat down on a chair and cocked an eyebrow at Sebastian. Seeing the look on his sister's face Sebastian sat up, "What?"

"Well, she now knows of your sexcapades," Kathryn said, voice smooth as silk.

"You told her?"

"Of course I did, darling. It wouldn't be fair to leave her in the dark now would it?"

Sebastian glared at her and pushed himself off of the couch. He stalked over to the stairs and started up them. Kathryn turned around in her chair, "Going off to write in your precious journal?"

Sebastian continued up the stairs without looking back at her.

"Could you be anymore gay?" she spat.

"Bite me," he growled back.

"Gladly."

Kathryn waited a few more moments until she heard the door slam. She sighed contentedly and quietly, to no one in particular, said, "We'll see Sebastian, we'll see."

--------

"You have siblings?" Spike asked incredulously, following Buffy through the graveyard.

"A twin sister and step-brother, yes. Now can you leave me alone?" Buffy said through clenched teeth, resisting the urge to stake him right then and there.

"Well, well, well… a twin you say?"

Buffy rolled her eyes, "You're almost as bad as Xander. Why are you following me? Leave."

"Can't a bloke help out a friend in need?"

"Friend? Spike, I'm the Slayer, you're a vampire. The only thing you should be getting friendly with right now is Mr. Pointy, here."

"Well Angel's being a vampire didn't stop you from getting friendly. More than friendly… shagging all the time."

Buffy stopped dead in her tracks and turned to face him, fuming, "Don't you _**dare**_ talk about Angel. You have no right. Besides, he was different."

"Oh yes… that soul of his. Just peachy isn't it? Aside from the fact that when he gets all happy inside he turns into a bloody mass murderer."

"Isn't that what you are?" Buffy stated coldly.

"Chip, love, remember?" Spike said, patting his head.

"Oh yes, so you won't react when I do this?" Buffy then punched him in the jaw, "Stop following me."

Spike touched his jaw, scowled at her, "Bitch," and walked away.

--------

"Good morning," Sebastian said cheerfully as he entered the kitchen.

"Mhm," Buffy responded, rather coldly.

_**The cold shoulder?**__** What could Kathryn have told her, exactly?**_ Sebastian asked himself.

"I was thinking," he voiced out loud, "that we could maybe go out for lunch today?"

"I dunno. Might have stuff to do," Buffy answered.

"That's not a nice way to show your guests around," he chided, "Besides I talked to Joyce, she says you're free."

"She would."

"Oh, rather hostile now aren't we?"

Buffy shot him a look, "Where's Kathryn?"

"Getting her 'beauty sleep'."

Buffy laughed at this. She looked at her 'brother'; he really did seem to genuinely want to have lunch with her. She sighed, "Fine, but Riley's coming too."

--------

The three of them sat down at a table at the Espresso Pump. The boys seemed less than thrilled to have the other one there, but tried not to show it. When the tall, skinny, boy with acne came over to ask for their orders Buffy ordered a red eye, knowing that this lunch was going to be a long one. The boys ordered drinks and sandwiches.

"Aren't you hungry?" They both asked Buffy at once, followed by threatening glares at each other.

"Not really," she answered, feeling the knot in her stomach clench even more.

"So how long have you two been together?" Sebastian asked.

"Nearly a year now," Riley answered with pride.

"That's a long time, congratulations."

"What's the longest one you've had?" Riley asked snidely.

"Not entirely sure to tell you the truth."

"So you're _**that**_ kind of – " Buffy slapped Riley's arm and he stopped, looking sheepish.

Buffy smiled at him and he added, "If that bruises… "

Sebastian smirked, "She a hard hitter Riley?"

"She's stronger than you'd think," Riley answered coolly.

--------

"I have to go out for a bit," Buffy stated, heading for the door.

"Again? Why so late?" Kathryn questioned, not really caring.

"I… I need some fresh air."

"Let me come with you," Sebastian said, standing up, "Can't be safe for you out there by yourself."

Buffy laughed, "You'd be surprised. But no, you should stay here."

"Too bad, I'm coming with," Sebastian grabbed his coat off of the hook and went out the door.

Buffy sighed and headed out the door after him, _**He better not get himself killed.**_

--------

"Do you take walks in graveyards often?" Sebastian questioned.

"It's a hobby," Buffy smirked.

She suddenly heard a rustling to the left. She whipped toward it and saw something move towards them. She shoved Sebastian, who fell to the ground with an "Oomph!" and ran at the beast. When they collided she looked up and saw it was… Spike.

"Bloody hell Slayer, what are you doing?" Spike bellowed.

"Shh! Keep it down," Buffy growled.

Spike saw Sebastian's form on the ground, pushing himself up. He looked at Sebastian for another second then realized who he was. "He's your brother? That bloody ponce? Why he's another Nancy Boy!"

"Spike… "

"What was that?" Sebastian asked, rubbing his forehead.

"I… uh… fell?" Buffy stammered.

"Who is this?"

"This is Spike."

"Spike?"

"He's… in a band?"

Sebastian looked at him curiously and could have sworn he heard him mutter something that sounded like "Nancy Boy hair gel".

"Well, we should be getting home, Kathryn's waiting," Buffy spoke.

"Oh, she'll be fine, besides I just met your friend here," Sebastian replied.

"No, get on home. I'll stop by sometime," Spike supplied.

_**Gosh I hope not, **_Buffy thought to herself.

--------

"Damn," Buffy muttered, taking off her coat and realizing she forgot Mr. Pointy at the graveyard, "I'll be right back," she announced, putting her coat back on.

When she opened the door Spike was standing there, "What do you want?"

"Hello to you too Summers," he held up his hand, "I found something of yours."

Buffy's eyes widened when she saw Mr. Pointy, "Thanks, well I guess you should – "

"Who's here?" Kathryn asked, walking up to the door. She raised her eyebrows at Spike.

Spike looked at Kathryn and smiled. She was Buffy's twin alright, but with differences. Some subtle, some not so. She was a bit shorter than Buffy and her face was more angular. She didn't have as much muscle as Buffy did, but carried herself well. There was also a colder air about her. She was someone Spike could see himself getting along well with.

"I'm Spike," he said, extending his hand.

"Kathryn."

"Well now that formalities are out of the way Spike should be getting on his way… " Buffy intervened.

"What're you holding?" Kathryn wondered, seeing the stake.

"I'm um… building a little fence?"

Kathryn rolled her eyes at her strange sister and turned back to Spike, "It was a pleasure meeting you. I'm sure I'll see you again sometime soon?"

"You bet, love," and with that Spike was gone.

--------

"And… and Kathryn said that he was a 'heartbreaker'. Will, I don't know what's going on with this," Buffy sighed.

"Well Buffy, you were the one who said 'But he's my brother. But I'm with Riley. But… but… '"

"But… but… "

Willow smiled at this, but her look then turned somber, "Well his reputation doesn't sound very good. He's probably not one to get tangled up with. And it might get kind of awkward with the whole sibling thing, but then again… no blood relation." Willow smirked at Buffy, "But you can always still look at him."

Buffy sighed, "And Riley."

"What about Riley?"

"He's been, different lately. There's times where I can't… oh, I don't know."

"Stick with him Buff, see what happens. I mean, Tara and I get into our little tiffs, but at the end of the day I know I still love her. And I'm sure the same goes for Xander and Anya."

"Yeah, I guess I just feel like he's hiding something."

--------

"Buffy!" Spike yelled, pounding on her front door.

"What!" She snapped, opening the door.

"You better come with me."

"Why?"

"Just… please, you need to see something."

Sensing he wouldn't give in anytime soon Buffy agreed and followed him out the door. They headed down to the docks and reached an old, abandoned warehouse. Spike pushed the door open and closed it behind them. Buffy took in her surroundings. The place was dreary and in disarray. It looked as if someone intended on making it into a house, but stopped half way through. She saw a fire burning in a garbage can. She went to ask Spike a question, but he pushed her into the next room. She saw a group of vampires sitting around a human, a seemingly willing human. She shuddered and let Spike usher her up the stairs, planning on taking the vamps out after she saw what she "needed" to see. Spike showed her to a door and Buffy pushed it open. It took her eyes a minute to adjust to the light, but what she saw next would forever be engraved in her mind.

"Riley!" she chocked out.

Riley was lying on the floor with his shirt off and arms extended. There were two skanky looking vampires on either side of him, sucking the blood from his wrists. The blonde girl on the right raised her head and smiled at Buffy, blood on her teeth, "You here to join, sweetie? I'm Sandy."

He looked up at her, and then to the two vampires, "It's not what it looks like."

"Oh… what? So these two _**very **_weak, not to mention slutty, looking _**female**_ vampires managed to capture and sedate you so they could... what?... take turns playing 'Who can drain Riley first?' I'm sure that's what happened."

Before he could say anything she rushed over to him and grabbed Sandy by her hair, hauling her up, "Alright bitch, I'll join your party." Buffy threw her against a concrete wall, which cracked upon impact. Sandy fell to a heap on the floor and started to stand up. Buffy roundhouse kicked her to the head and watched her fly back into the wall. She ran over and staked her quickly in her heart. Buffy's head snapped to where Riley and the other vampire were still sitting on the floor, "You get the fuck away from him." The vampire's eyes widened and she ran from the room.

"Buffy… " Riley tried.

"No!" Buffy pushed past Spike and down the stairs.

She raged into the room with the group of vampires and the human. She grabbed the human by his collar and threw him out of the room, "Get out. Run. Now!" The human stood up and raced out. "As for the rest of you… " she said, turning on the vampires. She grabbed the garbage can with the fire in it and threw it into the room. She watched as it lit on fire and as the flames licked the walls. She heard the vampires' screams and left the building.

"Slayer!" Spike called, chasing after her.

"Why did you show me that?" She growled.

"I thought you should know."

Buffy turned around, looked him in the face and then punched him in the nose, "Thank you."

--------

"What's wrong?" Sebastian asked as Buffy entered the house.

"Riley. It's over," Buffy stormed off up the stairs and slammed her door.

Sebastian turned to Kathryn, who was listening in the doorway to the kitchen, "And the game begins."

--------

**Author's Note:** Thanks so much for the reviews guys! I'm so glad I've been able to update like this… it's really nice! I'll do my best to update as often as possible! Hope you're liking it so far!

**Lexi**Thanks! This didn't seem to be a crossover that was often (or at all) done. Hope you continue to enjoy it!

**Allen Pitt: **You're great. I love the way you think. I think this story and its wackiness will prove to be very interesting… and rather confusing! ;-)

**Rightside**I'm glad you like it! And stick along for the ride… drama will shortly ensue.

**Chosenfire28: **Bye-bye Riley:-D

**Vik**Thanks!

Thanks everyone!


	4. Chapter 4

**Title: **Of Keys, Slayers, and Cruel Intentions

**Author: **Gabby

**Summary: **Instead of the monks making Dawn the key, Kathryn Merteuil is created to be Buffy's twin sister. And what happens when the handsome Sebastian Valmont is thrown into the mix? Spoilers for seasons 1-5 and Cruel Intentions.

**Rating: **R

**Disclaimer: **Not mine. All Buffy is owned by Joss Whedon. And Cruel Intentions is owned by…some other brilliant person who's name I don't know off the top of my head.

**Author's Note: **My first Cruel Intentions story, but definitely not first Buffy, first crossover, or first fanfic! I'll update as often as possible, if I don't it's because school or something interferes, I have the whole plot and story line down… it's just typing it and getting it posted. Feel free to leave comments and constructive criticism, but please no flames. Enjoy!

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Riley looked out of the helicopter, no sign of Buffy. He scanned the streets, no lone figure racing toward him. He shouldn't have expected it, not after what he did. Buffy didn't love him anymore, even after the letter. It was foolish to think a letter could get her back. Even if what he wrote was entirely true. He closed the door and sat back in his chair, wondering if he'd ever see the girl of his dreams again.

--------

Kathryn smiled as she threw the letter into the fireplace. To an outsider it might seem as if she was helping Sebastian, but she wasn't. Without this letter Buffy would have no form of closure and it'll be harder for her to trust again. She watched as the flames licked the sides and as the white paper turned into black ashes. The only recognizable thing left was Buffy's name scrawled in the middle of the letter, until a hold burned right through the middle of it.

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"Where's Kathryn?" Buffy questioned, coming down the stairs.

"I think she went out. To The Bronze or something," Sebastian replied.

_**Crap,**_ Buffy thought to herself, _**She**__** won't be able to defend herself… and considering she looks like me… **_

"Y'know… I think I'm gonna go out too," Buffy paused and looked at Sebastian, "Wanna come?"

Sebastian grinned to himself, "Sure. I'd love to."

They left the house and headed down toward the abandoned warehouse which was turned into The Bronze, pretty much the only cool place to hang out in Sunnydale. Aside from the Espresso Pump and of course… the graveyards. When they reached the club there was music pulsating from the inside. Tonight it was a DJ, no band. The end of Diamond Dogs by Beck was playing as they entered. It then switched to Beat City by The Flowerpot Men. Buffy moved with the music as she made her way through the crowd, searching for her sister.

Sebastian smiled as he watched Buffy in front of him. She seemed happier than she had been lately. And she seemed intent on something. He decided to act now. He grabbed Buffy's arm and pulled her back. She spun around and smacked into him. She laughed lightly and blushed, "Oops."

"Wanna dance?" Sebastian asked, grabbing on to her hand.

Buffy's spine tingled, "Um… sure. Let me put my coat down."

Buffy walked over to an open table and slung her jean jacket over a chair. She walked back to Sebastian and they headed out onto the dance floor. The song changed again, this time a fast, techno beat. They moved with the music, Sebastian's arms wrapped around her waist, and soon lost track of everything around them. Buffy didn't even notice as Kathryn left the club with a certain blonde vampire.

--------

Kathryn opened up her mouth to speak, but before she could say anything Spike had her up against the wall. It took her a minute to register what had just happened. Once she regained a sense of what was going on she started kissing him back. It was an intense kiss that didn't seem to be stopping anytime soon. Kathryn dropped her Dolce & Gabbana purse on the ground and wrapped her arms around Spike's neck. They stayed that way for awhile, as amused couples came and went. Spike finally pulled away. Kathryn caught her breath and fixed up her hair. Spike bent down, picked up Kathryn's purse and handed it to her.

"Goodnight, love," he said and disappeared into the darkness.

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Gunn walked down Sunnydale's main street. He saw couples holding hands and smiling. He saw families carrying shopping bags and talking. Then he looked for the things normal people don't see. The sulking figures in alleyways. The look of fear -- or the look of hunger -- on someone's face. As he walked past a dark alleyway he heard some scuffling. He doubled back and walked into it.

At the end Gunn saw a vampire and a petite blonde with her hair up in a ponytail. The vampire was advancing on her, but the girl didn't seem afraid. She actually seemed… excited? The vampire lunged at her and before it could do anything she roundhouse kicked it to the head. Gunn was in awe as he watched the girl fight the vampire.

The vampire threw punches, the girl blocked them and vice versa. The girl head butted the vamp and then quickly did a back flip, her feet kicking the vampire under the chin. The vampire flew backwards and slammed against the brick wall. The girl called out, "Honey! I'm home!" and threw her stake across the alley. It jammed into his chest and then fell to the ground as the vampire turned into a pile of dust.

The girl walked over and picked the stake up off of the ground. She pocketed it in her coat and turned toward the mouth of the alley.

"Shit," she stated out loud, seeing Gunn. "Look buddy… don't, y'know, say anything about this? I mean I'm sure enough people know already, but the last thing… "

Gunn cut her off, "You're the Slayer?"

The girl's eyes bugged, "Um… yeah. How'd you know?"

"Well… I've been fighting vampires and demons for awhile, y'know?"

"Sure… "

"And I always heard 'bout this girl that fought for our side. Killin' things and what not. Never thought she was real. And… look at you."

"Excuse me?"

"No offense… you just don't look like you could… do a lot of damage."

The girl smiled, walked over and punched him in the stomach, "My name's Buffy, what's yours?"

"Gunn," he croaked out.

"Pleasure. What're you doing here anyways? I haven't seen you around before."

"I'm not at the liberty to discuss that. 'Sides, why the hell should I answer you? You just punched me in the stomach."

"Oh, I'll find out. See you around," Buffy chirped and walked out of the alleyway.

"Ugh," Gunn slid down the wall, "That's gonna leave a mark."

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"So he could totally be related to our glow light?" Buffy asked, tossing the orb up in the air and catching it.

Giles gasped and leaned forward a bit, "Could you not? What if it breaks? We could all be thrown into another dimension."

Buffy pouted but held the orb still, "Fine."

Giles looked towards Willow, "Have you found anything on this orb?"

Willow shook her head, red hair up in a ponytail, "Nope, still looking though."

"So this man could potentially have something to do with this orb."

Willow nodded and started thumbing through another book.

Suddenly Xander ran into the room, "Quick! Turn on the television!"

The three that were currently there looked startled, but pressed the power button. On the news were at least ten people being admitted into the psych ward at the Sunnydale hospital. Buffy squinted and recognized one of them as the security guard from down by the docks.

"Hey!" she pointed at the man, "He's the guard that I saw when I found the orb!"

"Maybe he knew more than he was letting on?" Willow ventured.

"We should talk to him!" Xander voiced.

"Look at the state his mind is in, Xander," Giles stated, "I highly doubt we could get anything out of him."

"Well it's always worth a shot, Giles," Buffy said. "I'll see if I can get into the psych ward when I drop mom off at the hospital tomorrow."

"Hospital?" the other three asked, worriedly.

"Don't worry guys; it's just a routine checkup."

--------

Buffy made her way down the hallway in the psych ward. She was surprised the nurse had readily believed she was a family member of the security guard. Luckily she remembered the name she had read off of the name tag. She found the right door and made her way down the row. She finally found the man she recognized as the security guard and knelt down next to his bed.

"Hey, remember me?" Buffy asked soothingly.

"So bright, so bright," the man muttered.

"The orb that we found? Yeah… sure. Do you know what it happened to be used for?"

"So bright," was all the man could utter.

"What's so bright?"

"The key," the man on the other side of her practically bellowed.

She turned and looked at him. He had what Buffy would like to call "monk hair". She whispered to him, "The key is bright?"

"The key. Radiant."

"And… what is this key?"

"Protect," the man then looked at her and didn't blink once, "You must protect."

"Protect what?"

"The key. Slayer will protect."

Buffy gasped, "You know who I am?"

Then the man went into a fit and the security guard just kept mumbling "So bright". Buffy quickly left the room and saw a nurse walking by. She stopped him and quickly looked at his name tag, Ben. "A man in there is a having some sort of fit."

Ben's eyes widened and he ran to the room. Within seconds an alarm was sounding. Buffy figured she should get out of here before anything else went wrong.

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Buffy was lying on her bed, thinking about the night at The Bronze, when Kathryn came in.

"A lot on your mind?" Kathryn asked, barely caring.

"It's Sebastian," Buffy replied.

Kathryn cursed quietly to herself, _**He better not be getting to her already.**_

"What about him?"

"Well he doesn't really seem to be the way you described him."

"Oh, my dear sister. Let me share with you a few of Sebastian's exploits."

Kathryn then explained, in great detail, what Sebastian had done to the psychiatrist's daughter and to Cecile. When she was done she settled back onto her cot. She smiled perkily up at Buffy, "Any questions?"

"N-n-not really," Buffy managed.

She couldn't believe Sebastian was capable of that. Spike was capable of that, oh yes he was, but not Sebastian. Buffy must have muttered Spike's name because Kathryn had just quickly looked up at her and asked, "What about Spike?"

"Nothing. I was just… thinking," Buffy replied.

Kathryn narrowed her eyes; _**She**__** has another thing coming if she thinks she can get Spike. Besides, he's got me. What more can he want?**_

"Why do you ask, Kathryn?" Buffy wondered, suspiciously.

"No reason," Kathryn replied smoothly, "I'm going to go finish getting ready for bed."

Kathryn smiled to herself as she left the room and went down the stairs and quietly headed out the door, _**My**__** dear sister doesn't need to know my every move.**_

"Guess it's time for slayage," Buffy muttered and pulled Mr. Pointy out of her drawer.

She quickly exited her room, snuck past the closed bathroom door and headed out into the night. She made her rounds down by the docks; nothing. She checked out the upper parts of town; nothing. Then she made her way to the graveyards. She patrolled two, which yielded nothing except a pathetic excuse for a vampire. She reached the third when she saw something that made her stop in her tracks.

"Spike? And Kathryn?" Buffy gasped.

--------

**Author's Note: **Thanks so much for reading guys! I love your comments, they keep me going :wink, wink, nudge, nudge:.

**W1cked Angel: **Glad you like Spike! I have to say that's my favorite Spike too, before he goes all soft.

**Allen Pitt: **The monks are thinking "Flesh and blood relative! She'll protect her!", little did they know what Kathryn was like. So… we'll see how it pans out.

**Chosenfire28: **I wish she would have reacted that way too. I didn't like Riley; he just needed to get out of there. She should've seen that in the show too. :sigh:

**Krycek's**** Immortal Slayer: **Yes Riley is a dummy. And yes… now it's time for Sebastian and Kathryn's "game". And I suppose a bunch of people would like to see her get pummeled… it'd be highly entertaining. ;-)

**Summertime201 and ****Becomingwhaturmeantobe**Thanks so much for reading! Glad you're enjoying it!

**Everyone that's read: **Thanks!


	5. Chapter 5

**Title: **Of Keys, Slayers, and Cruel Intentions

**Author: **Gabby

**Summary: **Instead of the monks making Dawn the key, Kathryn Merteuil is created to be Buffy's twin sister. And what happens when the handsome Sebastian Valmont is thrown into the mix? Spoilers for seasons 1-5 and Cruel Intentions.

**Rating: **R

**Disclaimer: **Not mine. All Buffy is owned by Joss Whedon. And Cruel Intentions is owned by…some other brilliant person who's name I don't know off the top of my head.

**Author's Note: **My first Cruel Intentions story, but definitely not first Buffy, first crossover, or first fanfic! I'll update as often as possible, if I don't it's because school or something interferes, I have the whole plot and story line down… it's just typing it and getting it posted. Feel free to leave comments and constructive criticism, but please no flames. Enjoy!

-----------

Buffy paced her room, unsure what to do. _**What the… what the hell does she think she's doing? **__**Spike?**____**My goodness.**__** What does he think he's doing? Oh geez… **_

Buffy flopped down on her bed and buried her head in her pillow. She then opened her mouth and screamed. Even though the sound was muffled Sebastian heard her downstairs. He set down his journal and walked up the stairs. He peeked into her room quizzically. He saw Buffy's blonde hair splayed across the pillow and her face practically glued to it. Sebastian walked over and sat down on the edge of the bed. He tentatively touched the small of Buffy's back.

"What the!" Buffy shot up off of the pillow; make up smeared on her face.

Sebastian put his hands up defensively, "Sorry… are you okay?"

"Do I look okay?" Buffy snapped at him.

"Um… "

"Exactly! Now if you'll excuse me," Buffy jumped off of the bed, grabbed a pair of pajamas and stalked into the bathroom, slamming the door behind her.

Sebastian stood up and muttered "That time of the month?" and walked calmly out of the room and back downstairs to his journal. He eventually fell asleep on the couch and was only awakened when Kathryn snuck, not so quietly, into the house.

"Now, where might you have been? Hmm?" Sebastian asked, smirking.

"Wouldn't you like to know?" a rather disheveled Kathryn answered.

"Buffy's in a rather pissy mood, so _**try**_ and be nice when you go up there."

"What's got her knickers in a twist?"

Sebastian cocked an eyebrow, "I'm sure you know."

Kathryn "humphed" and headed off upstairs. She found Buffy sitting on the edge of her bed, staring at the door. Kathryn smiled, "Buffy."

"And how was your night?" Buffy sneered.

"Not very eventful."

"So that make out session was just a fluke?"

Kathryn gasped, "What… ?"

"Oh, I saw you and Spike going at it. Playing tonsil hockey. Don't act like you _**don't**_ know what I'm talking about Kathryn. What do you think you're doing?"

"Why is it any business of yours? It's _**my**_ life; I control it, not you. All you've succeeded in doing so far is getting in the fucking way."

Buffy spluttered, "I-i-in the way? All I've done is go out of my way to make you comfortable. I'm sharing my matchbox sized room with you, I'm making sure you don't get bored to death, and I'm putting up with your bitchy-ness. I don't think I could do more if you asked me to."

Kathryn was in shock; her sister had just told her off. "Well… why does it matter anyways that I'm with him?"

"You don't know what he is."

"Excuse me?"

"Nevermind."

--------

Spike was walking back to his crypt when he sensed someone, or something, behind him. He whipped around quickly and saw what was following him.

"Oh blood hell, what do you want?" he snarled.

"Blondie Bear," Harmony snapped, "What on earth were you doing with the Slayer? And what was up with her hair?"

Spike laughed, "The Slayer? No way… that was her twin sister," Spike put on a high pitched voice, "Kathryn".

"Who cares. What were _**you**_ doing with _**her**_?"

"I'm just trying to get to the Slayer. Besides, why do you care Harm? It's over."

Harmony sneered at him, "I'll get to the Slayer before you."

"Pfft, you're not even competition."

"Oh, you'll see Spike," she spat, "You'll see."

Harmony started stalking off and Spike called out, "Who's gonna help you, love?"

"My minions!"

Spike snickered to himself and muttered, "Harmony. Minions. What's next, pigs flying?"

--------

"Okay boys," Harmony stated, hands on her hips, "We're gonna capture and kill the Slayer."

"We are?" one of them asked dumbly.

"No Peaches, I just said that," Harmony hit him upside the head, "Yes we are!"

"How?"

"We're gonna kidnap her sister."

"She has a sister?" one of the others asked stupidly.

Harmony sighed, "A twin sister."

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Sebastian and Kathryn were sitting in the living room, watching TV, when a brick came flying through the window. Kathryn screamed and dove behind a chair. Sebastian slowly stood up and walked over to the brick. A note was attached. He pulled it off of the brick and opened it. In big loopy letters it read "Come on out Slayer".

"Slayer?" Sebastian looked confused, "Like that one band?"

"What was that?" Buffy yelled, running down the stairs.

Sebastian shrugged and pointed at the brick. He then handed Buffy the note. Buffy read it and looked at it quizzically. That's when they heard a voice from outside.

"Come on Buffy! I know you're in there!"

"Harmony?" Buffy asked, incredulously.

"Never thought you'd see me again huh?"

Buffy sighed, "Wish I didn't have to. And who are the other vamp-" Buffy stopped herself, "Who are the others with you?"

"My minions."

At this Buffy laughed until she cried. Sebastian looked at her in confusion. And all the while Kathryn had snuck out of the room, hoping to go find Spike. She walked to the back door, only to be caught by one of Harmony's "minions". He put his hand over her mouth before she could scream and drug her off into the night.

Harmony saw that Peaches had caught Kathryn and smirked at Buffy, "See you later, Slayer." She and the rest of her entourage then stalked off.

"Slayer? What-" Sebastian was cut off by Xander and Anya running into the house.

"What's up guys?" Buffy questioned.

"Harmony." Xander gasped, "Has. Kathryn."

"Shit."

"That little blonde girl?" Sebastian asked, bewildered.

"Oh, she's not just some little blonde girl," Anya stated, "She's a vampire."

Buffy, Xander, and Sebastian stared at her in shock; Sebastian's reason completely different than the others.

"She's kidding of course!" Xander practically shouted.

"I have to go get her," Buffy said.

"I'm coming with," Sebastian spoke boldly.

"Oh no you're not sparky," Xander chided.

"Xander… I think he should," Buffy muttered, "It's time. You and Anya watch the house, we'll be back."

--------

"What the fuck do you want?" Kathryn asked, hanging limply from the wall.

"To show Spike I'm just as good as he is," Harmony snarled, "And to get the Slayer."

"Spike? What does he have to do with this?"

"Blondie Bear has to do with _**everything**_."

"Blondie Bear?"

"While this is a _**thrilling**_ conversation, can we just get to the killing?" Buffy asked, walking into the room, Sebastian in tow.

Sebastian looked rather frightened with a cross in his shaking hand. His other hand was clutching a vial of holy water. His face was the color of printer paper. His heart was in his throat and he thought he'd pass out any second. The room was filled with people whose faces were distorted; one of his sisters was chained to a wall, while the other was wielding a rather nasty looking axe.

Kathryn's face morphed from one of fear into one of shock and awe when she saw her sister and brother enter the room. Buffy was holding a silver axe that glinted when the light hit it correctly. Sebastian looked like he was about to wet himself. If Kathryn herself wasn't so scared she probably would have laughed at him. She looked at the group surrounding her. Their twisted faces looked at her with hunger. She had no idea how Buffy was going to fight them, considering they had super strength. She learned this when they chucked her across the room and into a wall. There's no way her petite little sister could save her. They were all dead.

"Peaches, watch the girl," Harmony pointed at Kathryn, "I'll get Buffy."

"Wait… " Peaches drawled.

"What?"

"Which ones which?"

Harmony sighed, "If we had the Slayer chained to the wall do you really think I'd be fighting her right now?"

"No… "

"Exactly! Now watch her!" Harmony pointed to Kathryn again.

Harmony sauntered over to Buffy and looked her in the eye. Buffy's eyes narrowed and she quickly lashed out at Harmony, hitting her over the head with the axe. One of Harmony's lumbering lackeys ran over as he saw her fall to the floor. He ran at Buffy and knocked her to the ground. They wrestled and he wound up getting the axe from her, but before he could do anything Buffy kicked him in the stomach and he went flying. She jumped up and saw a wooden unicorn from a carousel among the plethora of unicorns that decorated the room. She ran over and broke it into a few pieces. Buffy threw one at Sebastian's feet and yelled, "If one comes at you, stake it!" She ran over to the vamp who stole her axe, who was now standing up, and kneed him in the groin. He howled and dropped the axe. She glared at him, "Ass," then quickly staked him and then picked up her axe. With a stake in one hand and an axe in the other she ran at the vampires who were guarding her sister.

Kathryn was struggling against the chains and the vampires leered at her. Buffy quickly attacked. While she was fighting them Harmony had gotten up and made her way over to a very scared Sebastian. He fumbled with the stake and wound up dropping it. Harmony kicked it away and growled, "You broke my unicorn." Sebastian shoved the cross in her face and as she backed away he threw the holy water at her. He heard steam hissing as the water burned her skin. Harmony shrieked and punched Sebastian in the jaw. He fell to the ground and didn't move. Harmony bent down to pick him up.

"Hey!" Buffy called.

"What?" Harmony snapped and looked up.

"Missing something?" Buffy held up in her hand the horn of the unicorn.

Harmony was about to retort, but quickly looked around. She noticed all her minions were dust. She backed up towards the door, "Until next time, Slayer," and took off.

Buffy sighed and broke Kathryn's chains, "Some people never change."

"Who were they?" Kathryn questioned.

"Vampires."

"And you… hunt them?"

"Something like that."

"Are there a lot of them?"

"You betcha."

"Have I ever met one before this?"

"I'd say so. Goes by the name of Spike."

Kathryn quickly shut up and followed Buffy as Buffy went over to Sebastian. She lifted him up easily and started out the door. Kathryn followed her like a puppy would its master.

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**Author's Note: **Hey! I know that this actually happens before Riley leaves and what not, but I reworked stuff… it seemed to work out better for my story. Thought I'd just point that out. Hope you're all enjoying it so far!

**Vik**Glad you like it! There'll be more about Spike and Kathryn's reaction to what he is coming soon, don't worry.

**Lifes****-Slayer: **I love the movie too! I'm addicted. Haha. And I'm not sure about Annette, I wanted to… but I'm trying to figure out how to work her in. If you have any ideas, let me know!

**Allen Pitt: **I was definitely in the "Riley Can NEVER Replace Angel" group. So… he's mostly doomed for me. And after your last comment… it sounds like this chapter was your kind of chapter. :-D Hope you enjoyed!

**Softly descending: **Thanks for reading! And I'm gonna hopefully work Angel into it more… still trying to work it all out.

**Chosenfire28: **Yeah, Kathryn doesn't seem to be doing herself much good. We'll see if she changes (or not) after all of this… hmmm. Thanks so much for reading!


	6. Chapter 6

**Title: **Of Keys, Slayers, and Cruel Intentions

**Author: **Gabby

**Summary: **Instead of the monks making Dawn the key, Kathryn Merteuil is created to be Buffy's twin sister. And what happens when the handsome Sebastian Valmont is thrown into the mix? Spoilers for seasons 1-5 and Cruel Intentions.

**Rating: **R

**Disclaimer: **Not mine. All Buffy is owned by Joss Whedon. And Cruel Intentions is owned by…some other brilliant person who's name I don't know off the top of my head.

**Author's Note: **My first Cruel Intentions story, but definitely not first Buffy, first crossover, or first fanfic! I'll update as often as possible, if I don't it's because school or something interferes, I have the whole plot and story line down… it's just typing it and getting it posted. Feel free to leave comments and constructive criticism, but please no flames. Enjoy!

--------

By the next day Sebastian had developed a nasty looking bruise on his jaw, but it didn't seem to faze him. Kathryn was holed up in her and Buffy's room, apparently trying to see if this whole situation would blow over, or hoping against hope that it was one bizarre dream.

Buffy was sitting in the kitchen eating a sandwich when Sebastian appeared in the doorway. Buffy set her sandwich down and looked up at him, "Can I help you?"

"Can you explain what you are exactly?" Sebastian blatantly asked.

Buffy was taken aback as Sebastian lowered himself into a chair on the other side of the island and looked intently at her face. She picked up her sandwich and took another bite. She eyed his face, he looked genuinely curious. Buffy sighed and again set down her sandwich.

"I'm a Slayer," she spoke.

"Could you be anymore vague?" Sebastian smirked.

"If you'll give me a minute… When I was 16 years old, before my dad divorced my mom, when I still lived in LA and went to Hemery High… where I was easily the most popular girl in school… totally surpassing Kathryn," Buffy went off on a tirade, seemingly reliving her life that seemed so long ago. "Well one day a man approached me on the steps to the school. He kinda gave me the wiggins. He had the whole tweed thing going on, which definitely wasn't something I was particularly fond of. Anyways… he comes up to me and tells me that I have a duty. That I, alone, am to protect and save the world from evil. I thought he was high. I got up and quickly left, but he followed me everywhere. I finally gave in when he mentioned the dreams that I'd been having and the birthmark on my shoulder. No one else knew about the dreams, and only my immediate family knew about the birthmark, considering I had it removed.

"He explained to me that in every generation there is a Chosen One. She alone will stand against the vampires, the demons, and the forces of darkness. She is the Slayer. He told me that I was she. I was intended to fight off all the evil baddies. I tried to tell him that I couldn't be, I was just Buffy Merteuil, not some super chick with powers. Merrick, that was his name, eventually took me out to a cemetery. I asked him what gave him the right to do all of this and he explained that he was my Watcher, he was intended to guide me and help me with my training. He handed me a stake, pointed to a headstone and told me to watch it. I sat there for a few minutes, thinking it was insane, when all of a sudden a hand popped out of the ground. I screamed and backed away. Merrick pushed me back forward and told me that it was a vampire. The creature clawed its way out of the grave and I was told to fight and kill it."

"How did it go?"

"Let's just say there could have been another Slayer called that very night. I kicked and punched and resorted to hair pulling. I eventually managed to stake the monster because I fell on top of it. After that night I trained with Merrick every day after school. I barely showed up to cheerleading practice anymore, my boyfriend at the time broke up with me and chose to go to prom with someone else, my friends thought I was a loner and took Kathryn under their wing, thus escalating her into the position I once was. I didn't care, I couldn't care. The only thing I could care about was saving the world, one vampire at a time. Then a new player came to town, Lothos. He wanted me dead and would stop at nothing to kill me. He threatened my family, my friends, and eventually killed my Watcher. After that, I snapped. I did all I could do to rid this world of Lothos. He attacked the prom with a group of vampires. I fought them and won. While doing this I also succeeded in burning down the gym.

"That's when my mom and my dad got divorced. I became Buffy Summers and moved to Sunnydale, where on my first day I met my new Watcher, who just so happens to be Giles, and was forced to continue. I died that year. For about a minute. Xander brought me back with CPR, but another Slayer had already been called. I met her my sophomore year, her name was Kendra. She was killed in another fight which is another conversation for another time. After Kendra was Faith, who went over to the dark side, wound up in a coma, and is now in a state prison in LA. So I'm still on my own, fighting for our side."

"Wow," Sebastian breathed. "That's a lot of pressure."

"Yeah, but I've managed to save the world from at least a dozen apocalypses so far, with the help of my friends of course. I think I'm doing pretty well."

"So all the fighting you did last night, that was all Slayer strength and training?"

"You bet."

"This is probably going to sound really corny, but do you think you could teach me a few things? Just so you know, in case I get cornered in an alley by some vampire who's attracted to my good looks?" Sebastian smiled.

Buffy sighed, "I can teach you a few things, I could probably use some more help out there. And now that they know who you are you're going to have to be able to defend yourself, and not just stand there like a helpless puppy."

"I did not stand there like a helpless puppy."

Buffy snickered, "All you were missing was the tail between the legs."

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Sebastian flew across the room as Buffy picked him up and tossed him. He smacked into one of the padded walls and fell to the floor. He groaned as Buffy ran over to him. She grabbed him by the collar and easily lifted him up, "Now punch me."

"What?" he muttered.

"Punch me damn it, do it."

Sebastian pulled a fist back and went to punch her, but before he could even come close to her Buffy fan kicked his hand away. He yelled and spun around. Before Buffy could do anything Sebastian whipped back around and kneed her in the stomach. Buffy grunted and fell to her knees. Sebastian took this to his advantage and pushed her onto back and pinned her to the ground.

"Good one," Buffy stated, "You caught me off guard."

Sebastian smiled and went to respond, but before he could Buffy wrapped her legs around his torso and flipped him over onto his back, pinning him down, "Right back at ya."

Sebastian tried to get up, but Buffy put her hands on his shoulders and pushed him back down. She leaned down and whispered, "I won."

Sebastian then caught her eyes with his. Buffy's face was centimeters away from his, but she couldn't move. They stayed like that for about a minute until Giles came into the back. They instantly broke apart and moved to different sides of the room. Giles apparently didn't notice a thing.

"How is he doing?" Giles questioned.

"W-w-well," Buffy stammered, "He's doing well." She glanced at Sebastian across the room, "But I think we're done for today."

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"Oh Willow, I don't know what I'm getting myself into," Buffy sighed, holding a pillow tight to her chest.

She was sitting in Willow and Tara's dorm room. Willow was sitting across from her on the bed and Tara was on her bed, reading from an ancient spell book. Willow frowned a bit and started chewing on her lip.

"I'm not sure what to say Buff," Willow started slowly, "You just got out of a long relationship and no one can say that it ended well. And this could just be a rebound relationship just waiting to happen."

"Not to mention he's my step-brother."

"Cut it with the step-brother crap. He's not blood related. And you've seen Clueless right? Hello."

Buffy sighed, she couldn't believe Willow just made such an idiotic pop culture reference, it wasn't like her.

"You should have seen the way he looked me in the eyes. The only thing is… he has a reputation, and it's not a good one."

"Have you ever let that stop you before?"

"Not really… "

"There ya go. Just let the chips fall, Buffy."

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Gunn was patrolling one of the many Sunnydale graveyards when he saw the Slayer again, this time she was accompanied by-

"No way in hell," Gunn breathed.

There was Sebastian. The whole reason Gunn was here. He had to teach that punk a lesson. It's the least he could do for Ronald.

Buffy saw Gunn across the graveyard and quickly pushed Sebastian in another direction. She still didn't know if the strange man had anything to do with the orb and she didn't want to face him when she wasn't prepared.

Sebastian spotted Gunn, but wasn't aware that he was hunting for him. He quickly started walking in the direction Buffy pushed him, sensing that the other man was not someone they wanted to mess with right now.

Gunn started following the pair through the graveyard, all the while wondering what Sebastian was doing with the Slayer. He was careful not to draw attention to himself; he didn't want to go around sporting nasty welts for the rest of his time here.

They turned a corner when a vampire attacked. It flew at Sebastian and tackled him to the ground. Sebastian punched it in the nose and it howled in pain. Sebastian quickly got up as Buffy roundhouse kicked the vampire a few times. The vampire got a good kick in and Buffy went flying against a headstone. Sebastian ran over and kicked it behind the knees. It yelled and fell to the ground, where Sebastian quickly staked it. He stood up and brushed the dust off of him.

"How was I?" he grinned.

"Brilliant," Buffy beamed.

_**He fights vampires now too? What **__**the fuck**__** is **__**goin**__**' on 'round here? **_Gunn thought to himself as he walked off into the night.

--------

"Crap," Buffy said.

"What?" Sebastian wondered as they walked home.

"Kathryn's cross, it fell off somewhere back there."

Sebastian's face paled, "Why did you have her cross?"

"Well I thought it was rather pretty… Do you think she'll be upset?"

Sebastian laughed at this, "No, not at all."

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"AH!" a shrill high pitch voice screamed.

A body fell to the ground with a thud, alive but clearly insane, eyes rolling around in its head.

"Maybe, most magnificent one," a strange little creature spoke, "we should call a hospital, so the poor creature has somewhere to go."

A thin, beautiful, blonde woman turned toward the creature. She smiled for a moment before it turned into a frown, "Excuse me Jinx. But is that what we're here for, to help the weak? I don't think so."

"Yes, ma'am."

"That's better. Ah… I feel so refreshed, renewed. Now… I say we find that key."

"Yes, Glorificus."

"How many times have I told you!" the woman bellowed, "Call me Glory."

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**Author's Note:** Hey everyone! Hope you enjoyed it! Sorry it took longer to get up and that it's a bit shorter. I'm going to be gone from the 31st to the 3rd. So hopefully when I get back I can get another one up. Comments would definitely inspire me! Thanks for reading!

**Allen Pitt: **Haha, the Buffy-bot. That would be quite entertaining. I love your version of the final scene, it's absolutely amazing, it cracked me up. And we'll see how Angel responds… quite soon.

**W1cked Angel: **Well she hasn't **openly** done it…

**Chosenfire28: **We'll find more out about Kathryn later… and I'm liking this new "I'm strong" Sebastian. :-D

**Vik**Thanks so much!

**Softly descending: **It's not B/A, but trust me… there will be some definite B/A undertones 'cos they're my favorite couple. And thanks!


	7. Chapter 7

**Title: **Of Keys, Slayers, and Cruel Intentions

**Author: **Gabby

**Summary: **Instead of the monks making Dawn the key, Kathryn Merteuil is created to be Buffy's twin sister. And what happens when the handsome Sebastian Valmont is thrown into the mix? Spoilers for seasons 1-5 and Cruel Intentions.

**Rating: **R

**Disclaimer: **Not mine. All Buffy is owned by Joss Whedon. And Cruel Intentions is owned by…some other brilliant person who's name I don't know off the top of my head.

**Author's Note: **My first Cruel Intentions story, but definitely not first Buffy, first crossover, or first fanfic! I'll update as often as possible, if I don't it's because school or something interferes, I have the whole plot and story line down… it's just typing it and getting it posted. Feel free to leave comments and constructive criticism, but please no flames. Enjoy!

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"Sebastian!" Kathryn's shriek echoed through the house.

Sebastian came running into the room that Buffy and Kathryn shared. "What?" he gasped.

"Where the _**fuck**_ is my necklace?!"

Sebastian paled slightly, but caught himself. "Maybe it fell off when you were out?"

Kathryn snorted, "Me?"

Sebastian rolled his eyes at his coke addicted sister, "Don't worry, _**sis**_. I'm sure your stash will show up eventually. Or we could stake your little friend Spike and you could snort his ashes."

Kathryn bared her teeth, "Dick."

"One which you won't be seeing anytime soon."

Kathryn snarled and threw a Jimmy Choo stiletto at his head. He quickly ducked it and slammed the door behind him, calling back "Bitch!"

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"Buffy!" Sebastian called, walking into the kitchen.

He found her sitting on one of the stools by the counter. Her eyes were puffy and her cheeks were tear streaked. She looked at him, then quickly turned away and wiped her cheeks with the back of her hand.

"Buffy," he said, walking over to her and putting a hand on her shoulder, "Are you okay?"

"I don't really wanna talk about it right now," she stated, staring into space.

"Okay, but I've got something to take it off your mind."

Buffy perked up a little bit, "What's that?"

"Kathryn is freaking out about her necklace."

Buffy groaned, "Do you think she'd notice if I bought her a new one that looked just like it?"

Sebastian smirked, "Hell yes she would notice. It's special… "

"Special?"

"I'm going to let you in on a little secret, since you let us in on one. Our lovely bitch of a sister is a coke addict."

Buffy cocked her head to the side, "That explains a lot."

Sebastian laughed, "Come help me find it?"

------

"And they sent me to a doctor because they thought I was crazy, writing about vampires and demons in my diary. They sent me to a clinic, I was there for weeks. They stuck me with needles so many times and did so many tests that I finally just stopped writing about it, acted like it never happened. That appeased them. But you think they'd question all the ripped and bloodied clothes right? Never, not once. Sunnydale gave me a chance to start over. Mom was obviously still oblivious, until the end of junior year."

"What happened then?" Sebastian asked, looking up at Buffy sitting on the tombstone from his position on the ground.

"My then boyfriend went all monster on us and I had to save the world. She wound up seeing me stake a vampire on our front porch and I couldn't exactly pretend _**that**_ didn't happen."

"Boyfriend? Monster?"

"Ready for a sob story?"

Sebastian smiled a winning smile up at her, "You bet."

"Angel was his name. He was a vampire, but with a soul. He had fed on a young gypsy girl who was the favorite amongst their clan. They cursed him with a soul so he could feel remorse over every person he had ever tortured or killed. Which was a lot, considering he was called the Scourge of Europe. Eventually he wound up over here and in Sunnydale. We teamed up to fight all the big nasties and fell in love. Then my birthday came around and there was a big to do, but there was also some pretty bad shit going down involving Spike and his girlfriend, Drusilla. She had a demon called the Judge sent in for her birthday. Let's just say he was an ass. So Angel and I went to fight him, got captured, got away and wound up at his apartment. We both realized how close we'd come to dying and the time was right and we… "

"Made love?"

Buffy nodded, "I guess it happened during climax… or maybe after? I'll never know, I never asked. But Angel lost his soul."

"How?"

"According to the spell if he ever experienced a moment of perfect happiness he would lose his soul. A moment of perfect happiness defeats the point of the spell, which is to punish him. So then he turned back into the evil soulless vampire he once was: Angelus."

"Oh. So… how did this relate to your mom finding out?"

"Angelus wanted to bring a demon to wreak havoc on the earth and destroy it completely. Its name was Acathala. So we were fighting against him and basically every other vampire who knew about it. Hence the one showing up at my house. And my mom seeing."

"How'd she react?"

"She told me to get out and not to come back. I wound up in L.A. for the summer, living in an apartment and working as a waitress. Then I realized I couldn't run from everything and came back. She opened up to it then, realizing it was a part of me. And it's been so nice having her know… not having to hide… I just wish I could help her like she's helped me over the years," Buffy said tearing up.

"Are you okay?" Sebastian asked quickly, jumping off and brushing off his Brooks Brothers khaki pants. "Does this have to do with earlier?"

"It's my mom. She's sick. They… they think there's something in her brain. They need to do surgery. I just found out this afternoon."

"Buffy," Sebastian soothed and wrapped her in an embrace.

Buffy's body started shaking and was racked with sobs. She muttered unintelligibly into his coat. She pulled away from him, wiped her eyes and looked up at him, "Sorry. Didn't mean to break down."

Sebastian smiled at her, "It's alright. Everything will be alright Buffy, the surgery will go well and you can help her get through this. You're the strongest person I know, in more than one way."

Buffy smiled weakly at him and went to speak, but before she could say anything he put a finger up to her lips, silencing her. She looked at him quizzically as he leaned forward. He gently kissed her on the lips. When he pulled away she was still staring at him. Sebastian wasn't sure if that was the right thing to do until she grabbed him. Her kiss wasn't gentle. It was passionate and energetic and sent shivers down his spine. His tongue danced with hers as she ran her fingers through his hair. He hoisted her up and then pushed her up against the nearest mausoleum. He made sure her feet were on the ground and let her go. He started unbuttoning her jacket, but Buffy quickly pulled her mouth from his.

"Wait, what're we doing?" She panted.

"Um… I thought it was rather obvious," Sebastian replied, kissing her neck.

"But you're my brother and I'm emotionally bruised and I just got of a long relationship and I don't want to use you and… " Buffy babbled.

"Right now, I don't care."

He pressed his mouth against hers again and continued to unbutton her jacket. He cupped her breast as she bit his lip. He let his hand linger a little longer and then pulled it away, "We should get home. Give Kathryn her necklace."

"Mhm," Buffy nodded and quickly buttoned up her jacket.

Sebastian grabbed her hand and they left the cemetery together.

--------

"What the hell?" Gunn said as he watched Buffy and Sebastian leave the graveyard.

"She's with him? This is gonna make my job a hell of a lot harder. I guess if worse comes to worse I could always call for back up. Angel would be ready and willing."

--------

"Here's your necklace," Sebastian said, throwing the coke filled cross onto Kathryn's cot.

She smiled slyly at him, "Fuck her yet?"

"Very funny, but no."

Kathryn pulled on a black Marc Jacobs boot and looked at him, "Too bad."

"Where the hell are you going?"

"Out."

Sebastian shrugged and watched her prance down the stairs.

"Well that's good I guess," Sebastian said to himself, "That way she won't hear anything about Buffy and I. Yet."

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"So, you're a vampire," Kathryn said, raising a perfect eyebrow at Spike.

"You bet, love," Spike said, watching her atop of the sarcophagus.

She was wearing a short flouncy black dress and sexy stiletto boots. She had her hair up and Spike just wanted to take it down and run his fingers through it. He tossed back another shot of whiskey and slammed the glass down. If he couldn't have Buffy he could have the next best thing. And she was pretty fucking hot, so it wasn't that hard to get very aroused. He walked over to her and pulled the clip from her hair.

"Hey," she snapped, "What are you doing?"

"Shut up," he snarled, smelling her neck.

Kathryn smiled to herself. She hadn't even been here for two weeks and she already had someone dying to sleep with her. The fact that he was ripped and British also turned Kathryn on, so this would probably be rather enjoyable.

"Do you always have sex on top of your coffin?" Kathryn smirked.

"Like hell I do."

Spike lifted her up and carried her downstairs. He delicately set her on the bed. She leisurely leaned on her side and propped her head up with her hand. Spike leaned against the wall and looked at her hungrily. Kathryn sat up and slowly unzipped her boots, revealing her toned calves, and threw them on the floor. She leaned back against his red satin pillow and covered a fake yawn with her newly manicured hand.

"Tired," she stated, closing her eyes.

"Tired, eh?" Spike asked, crawling up on the bed toward her.

He placed his hands on other side of her head and leaned down. He kissed her viciously and quickly pulled away, "How about now?"

Kathryn wrapped her arms around his back and pulled him down on top of her. His tongue quickly found hers and they were engaged in an intense make out session. Suddenly she pushed him away. He glanced at her, questioning. "Let's cut the chicken shit," Kathryn smiled and she unzipped his pants.

Spike laughed and pulled the flimsy, little black dress over her head, revealing sexy La Perla undergarments. He groaned slightly and she pushed him over on his back. She quickly stripped him of his shirt and pants, revealing… nothing. Kathryn smiled and unhooked her bra. She giggled slightly when she saw how much that excited him.

"Ready for the night of your life?" She purred.

"I've been around for a longtime, pet. You have a lot of things to compete against."

"Oh, I'll win."

--------

Gunn saw what looked like the Slayer walking into a crypt with a bleach blonde vampire. She looked like Buffy, but her hair was brown and she was dressed in a way he wouldn't expect the feisty blonde to dress. He shook his head; he needed to figure out what the hell was going on.

"This town is fucked up," he sighed. "And that's saying something for someone who comes from L.A."

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**Author's Note: **Hey guys!!! Sorry it's taken so long for me to start writing again! So many crazy things have been going on. But I'm gonna stick with this story and finish it, so please bear with me! Thank you so much for all the feedback and comments! Hope you enjoyed it! Get ready for the next chapter!


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